Meredith shook her head, then nodded, remembering. ‘Yeah, just briefly. I went and sat on the roof for a while, reading in the sun, then Paula – you know, Ralph’s wife … widow … came over in the afternoon. She was in a state and just wanted to drink wine and cry. She wanted me to get drunk with her, but I didn’t want to. I can’t drink in the daytime; it gives me a headache. I had a glass, though, to keep her company. That’s when I saw Andy … Andrea. She was accompanying one of her clients off the boat, then she came over and asked after Ralph, if he’d been found. She saw that Paula was upset, and I told her I’d fill her in later. She went back to her boat and I walked Paula home.’

‘And how did Andrea seem?’

‘Absolutely fine, then and in the evening.’ Meredith paused and looked up, her eyes huge and grey. ‘Please tell me – can you be sure that she didn’t just fall in and hit her head on the way?’

Gemma held her gaze. ‘From the nature and position of the blow to the back of her head, the pathologist’s opinion is that it’s highly likely someone inflicted that injury on Andrea prior to her falling into the water.’

Meredith’s good hand stole contemplatively up to the back of her own head as if in sympathy. ‘It’s so horrible.’ Then she froze. ‘Oh God,’ she whispered, ‘I’ve just remembered something I forgot to tell you last time. It might be nothing … but…’

‘Anything you can tell us could be helpful.’

Gemma saw a very faint stain of pink rise on Meredith’s cheeks. Guilt, at more stuff she hadn’t told them about?

‘The other day – last week? – Andrea trimmed my hair for me, in her salon on the boat. It was after Ralph went missing, but I didn’t think anything of it, not really. I thought I’d imagined it…’

Gemma shot a glance at Mavis, but he was staring intently at Meredith.

‘Go on,’ he said, in an uncharacteristically gentle voice.

‘It’s just that I could have sworn I saw someone passing the porthole – a flash of a leg, like someone was walking round the edge of the boat.’

Mavis somehow managed to combine a neutral expression with one of scepticism. Gemma wondered if he knew he was doing it. ‘What time of day was this?’

‘That’s the thing – it was only about four in the afternoon, broad daylight, and I really doubt that her murderer would be strolling round the edge of the boat for anyone to see. They’d have some nerve, if they were. I just thought I should mention it.’